This report summarizes the results of scientific core drilling undertaken primarily to gain a better understanding of the bedrock geology in north-central Minnesota. The drilling and concomitant mapping were supported by the Minerals Diversification Program of the state legislature. The study area lies in southern Koochiching, northern Itasca and east-central Beltrami Counties. This region was selected because data are suggestive of mineral resource potential, but existing geologic maps were too generalized to guide private minerals exploration efforts. The thick cover of glacial deposits in this region requires bedrock geologic mapping to be based largely on the interpretation of geophysical maps. Core drilling and outcrop mapping identify the rock types responsible for the geophysical patterns. It is hoped that geologic mapping by this method will encourage private minerals exploration. In addition, this mapping is an acceleration of on-going efforts by the Minnesota Geological Survey to produce accurate geologic maps of the state to meet existing and future societal, academic and economic needs. The resulting bedrock geologic map at 1:250,000 scale has been released as Minnesota Geological Survey Open-File Report 89-1 which is being reviewed before formal publication. In the course of the drilling program much information was acquired regarding the thickness and lithology of Quaternary surficial deposits and the locally thick weathered bedrock materials (regolith). No formal plans exist at this time to publish an interpretation of these data, but the data are presented here on the geologic logs.